A 13 to 18 meter Victoria Lake cargo dhow normally has 6 to 8 crew. When you
have a winch to lift the sail and no cargo to handle, 3 crew can handle it, 2
can reach a safe place when one gets disabled.

Basic terms (see picture below). In the lateen rig, the gaff (folmali) is hoisted at its middle to the
mast top by the chalali(halyard). Then its front end is pulled down to the bow
by the josi. Near the josi departs also the kamlawa, pulling the down-front end
of the folmali rearward. The balazi prevents
the top half of the folmali from bending leeward in strong wind. The sheet
pulling the rear down side of the sail to the stern is called demani. A
folmali consists of two joined young
eucalyptus stems, and bends smoothly. The mast (mlingoti) is made of an older eucalyptus
stem. (Dhow logbook:
Making Mast and Gaff) Not meant to bend, the mast is shored up with four yali (stays). The front
two of them (here green and red) are always spanned at the luff (windward) side.

The dhow has no keel and can not go against the wind. From the point in the
middle of the picture below, directions in the red sector are not feasible. At
beam reach, the extreme, drift is 10 to 20 percent., so it looks as if you are
going against the wind but you are not.

Changing sail side from one board to another is intricate. Tacking (turning windward to
get the wind on the other board) is impossible. You have to turn the other way:
gybe. The
intriguing procedure of lateen gybing is explained below

The standard winds are such that while sailing on the lake
you should stay within 50 km from the lake shores to profit from the daily
pattern of thermal winds. In the middle of the lake, you often have no wind at
all, or from directions of which no predictions are available. Relatively warm
air tends to rise - tending to escalate into tropical rainstorms. On the earth
surface this rising warm air is replaced by relatively cold air (which is
heavier). The lake water is not much influenced by the daily heat of the
sun. Under the sun the land surface, now rain forests are largely
destroyed, gets too hot to walk on bare feet. And it gets much colder than the
lake water in the night. So, the daily pattern is:

The supreme moment: between 4 and 5 folmali flips from port to
starboard over mast-top. Demani (green) walked from port to starboard rounding
the mast and the folmali

Pull all and you are over starboard

The transition from 4 to 5 minimally requires Bf 2 wind to blow
the folmali free from the mast. Under Bf 2, when you have a big dhow: no gybing!
During the operation also the yali (stays) have to be moved from the
starboard to the port side.

The backstays (blue) do not move. Going to stage 2 the backward
starboard front stay (red) is untied on deck and moved to the opposite board to
become the forward port front stay. Going
to stage 6 the forward starboard front stay (green) is untied on deck and moved to
the opposite board to become the backward
port front stay.

Lateen rigged caravels were used in the Portuguese naval
explorations initiated by Henry the Navigator. Bartholomeus Dias and Vasco da Gama,
used them. Changing boards, caravels had three lateen rigs to gybe, which must
have required quite some crew training. We have some technical doubts about the
Portuguese caravel model we found on internet. For instance, we do not believe
you can gybe if your mast top sticks out so high above the gaff (folmali). But
the model is beautiful and not far
off: